Pages

Wednesday, 3 January 2018

HMS Terror makes you work for the time you spend with her. Part
1 of this post detailed how the planking of my model became a race against the
opening date of the Death in the Ice Exhibition, where it has been on display
for the past six months. “Below decks,” in my small basement workshop, where
I spent night after night fretting about the future of my little model, I admit
to acquiring a dim simpatico with the men who lived and worked on HMS Terror.
As I have described previously, the distinct and intricate nature of Terror’s hull planking was something I had intended to replicate from the very beginning of
my build. However, duplicating its complexities to scale, which required a
fully doubled-hull, with the second layer composed of unusually thick planks,
and on an extreme deadline, was folly that ultimately led to an eight-month modeling marathon.

In Part 1, I described how I replicated Terror’s
double-planked hull, where the vast majority of my effort was expended. In this
post, I will outline the planking of her upper deck,
the transom, and the ice channel that surrounded the ship.

The contract for Terror’s sister ship, Beelzebub, (1) describes
that her original upper deck (1813) was clad with fore-aft laid planks three
inches thick, while two and one-half inch planks covered her quarterdeck and
forecastle. In 1836, Terror’s forecastle
and quarterdeck were unified to create a new weather deck (upper deck), which
was re-clad in new planks and then doubled to increase strength. Rice, the Master Shipwright who was so
often associated with polar conversions of the era, described the unique
qualities of this new deck (2).

“The central planks of the weather deck are six inches thick,
laid fore and aft; the remainder of the deck is wrought double; the lower
planks, three inches thick, are laid fore and aft; the upper planks, three
inches thick, diagonally, having fearnaught dipped in hot tallow laid between
the two surfaces”

The first step in planking the upper deck involved adding the waterway, a plank which acted as a transition
plank between the horizontal deck planking and vertical bulwark planking. Luckily, on Erebus and Terror
this was simply a beveled affair. Note the interior view of the stern lights. You can see here how
I sanded the interior surface of the panes to simulate frost (and hide the interior).

Clamping the waterway at the bow - I always over clamp and over glue. Note the bow filling blocks.

As described by Rice, and as shown in the midship cross section
plan (3), the upper deck of HMS Terror was very unusual. Eleven massive central
strakes were laid fore and aft, providing significant rigidity. The central
seven strakes were made from “fir”, likely Canadian pine, and were six inches
thick and nine inches wide. These central stakes were flanked on each side by two
strakes of six-inch oak, each ten inches wide. Contiguous with the central
strakes were two layers of three-inch fir which covered the remaining deck
area. As described by Rice, above, the lowermost layer was laid fore and aft,
like traditional deck planking, but the uppermost layer was laid diagonally to
increase strength. The width of these planks is not shown in any of the
contemporary plans. Scribing marks on the 1839 HMS Erebus model indicate a
width between ca. six and eight inches. Recently a pine plank fragment was discovered at the Canadian Museum of History which may be a deck plank; this measured three inches by seven inches. As a result, I have
chosen seven-inch planks to represent the upper layer of deck planking.

Upper deck planking began by laying the "king plank", or the midline strake. Note here that the upper deck wasn't
double-planked. I had always intended to single-plank the upper deck, as holly is a quite expensive raw material.
Here, the central strakes are just three scale inches thick, instead of six.

After the careful spiling and slow progress on the hull, I
looked forward to Terror’s upper deck, which was covered exclusively in
straight, flat strakes. The central strakes, laid fore and aft, were a pleasure
to complete. I expected the diagonal planking to proceed similarly, but soon
realized that cutting the precise angles and lengths for each plank was not
only meticulous, but extremely time consuming. Each plank had to be cut to a
precise length, with angled butts that required very careful measurement.

The completed central planking. The odd and unsightly shift of butts is explained below.

As I was laying out my planking plan, and comparing it to
the contemporary sources, I gained some insight that could only be obtained
through building a model. I had often puzzled why only a few butts (plank ends)
are inscribed on the central strakes of the 1839 builder’s model of Erebus.
This struck me as odd, because the model was carefully inscribed to show the
details of the upper deck planking, and the butt ends of the central strakes
were crucial to a strong design. I originally believed it must have been an
oversight by the model maker, but in planking my model I came to understand
that the 1839 model is very accurate. To put it simply, there were so many
fittings on the upper deck of Terror and Erebus that the center-most strakes
are constantly interrupted. Consequently, butts could fall naturally on hatches
and companions, with no plank being greater than ca. 20 feet in length. Adding
a shift pattern would have been unnecessary, and in fact would have weakened
the vessels.

The diagonal planking began at the bow. Each plank had to be carefully measured and cut to fit precisely. I wasn't always
as successful as I would have liked. To simulate caulking, each plank edge was rubbed with a standard pencil. Sanding
removed the glue and pencil marks, leaving a crisp edge.

A closeup of the bow planking prior to sanding.

The completed upper deck planking with various cutouts underway. Some sanding is still required.

My next task was to plank the continuous ice-channel, or “ice
bumper,” perhaps the most identifiable feature on HMS Erebus and Terror. Since
the time of Parry, polar discovery ships had chocked in and planked over their
channels. The solid channels were necessary to prevent the chain plates, which
anchored the mast shrouds, from being caught and destroyed on icebergs or by other
ice conditions.

In 1835, Terror’s ice channels were simply six large, unglamorous protuberances at the position of the chains. In 1839, Rice filled in the spaces
between the individual ice channels to form a sort of smooth tapering bumper
that surrounded the weather deck of the ship. As Rice described (Ross
1847:328):

“…The ship is fortified externally by solid chock channels,
the spaces between the channels being similarly fitted, tapering at the
extremities, so as to form an easy curvature in a fore and aft direction…”

Planking the ice channels began at the bow, which required soaking, heat bending, and crimping to create the proper shape.
After the first plank, I realized that sanding the upper strake down to the height of the chocks was easier, hence the
wider strake behind the first.

Terror and Erebus had a white stripe painted along their ice channels. Here, I've simulated that colour shift with holly.
Holly provides a beautiful contrast to the Swiss pear of the hull. Note that the second planking below the wales
hasn't been installed in this photo.

Planking continues. The arrows remind me which end is up while I'm installing the planks. The upper surface of the
planks often had to be beveled to provide a close fit.

The completed ice channel at the bow. This image shows just how much the channel overhung the hull in this position.Erebus and Terror had a third layer of planking at the bow which filled in this gap. The iron plating was attached to
the third layer of planking.

The planking over the chocks was massive; six inch planks
covered both the upper surface and sides, creating a “bumper” that extended
approximately two feet from the side of the ship. The bolts which held the
chain plates in place penetrated through the planking, chocks, and frames and
were anchored on the interior of the vessel. This created an unbelievably
strong arrangement, making the chain plates, and thus the shrouds they
anchored, very unlikely to be damaged.

Adding the upper horizontal plank on the ice channel required careful measurement of the curves. Here I used a contour
duplication gauge to transfer the curve to card stock.

Checking the accuracy of the measurement.

Clamping the horizontal strakes in place. The midships section plan (3) shows that these were made from one extra
wide plank. More sanding is required here on the vertical surface to get the bow curvature just right.

Macro photo of the transition from the ice channel to the hull planking.

The completed ice channel. Note the "bumpy" lower edge hasn't been sanded yet, and will ultimately be hidden
by the bow plating.

Compared to the stern, planking the chock channels was a
pleasure. The only tricky operation was the upper horizontal strake, which
required special measurement to cut to the proper shape. Similarly, the large
fashion piece, so prominent on Stanley’s contemporary images of Terror, was also
challenging to implement as it had to be steamed and bent to accommodate the
gentle curve from Terror’s topside planking to her wales.

The fashion piece was a large vertical plank that protected the butts of the transom. It
was a particular feature of Erebus and Terror, visible on many of Owen Stanley's
period sketches and paintings. On Erebus and Terror it was painted white, so I used holly to replicate it. This shot was taken prior to final sanding and finish.

Terror's simplified transom. Without access to precise data on its arrangement, I kept it very simple. This picture was taken
before the double hull planking was completed. Note the doubled windows, which were characteristic of Polar discovery
ships since the time of Parry.

Terror's final planking configuration. Mini-Crozier for scale.

With the fashion piece installed, I completed the great planking of 2017. How
the master shipwrights sheathed HMS Terror's complex curves with oak planks eight inches thick is
remarkable to me. Believing that I could replicate their skill, even at 1/48th
the size, was simply an absurd folly on my part. To meet the deadline of the
exhibition, it was necessary that I work every spare moment I possessed for
nearly eight months. An added injury was the necessity to cut corners on the
lower layer of planking that has left me somewhat dissatisfied with my model.
While I believe the result is very acceptable, the trial is something I’ve yet
to recover from (and in fact is one of the reasons my blog has been so quiet
over the last few months).

While my endurance was tested, the ”great planking” imparted
an appreciation for the complexities of Terror’s extreme construction, as
well as for the skill of the master shipwrights and carpenters who designed and built
her. Like all wooden sailing vessels, much of Terror’s strength came from her
planking. That she survives intact today, after being subjected to perhaps the
worst ice conditions ever suffered by a wooden sailing vessel, is a testament
to the shipwright’s art.